Dr Fadl helped Osama bin Laden create al Qaeda and became the group's intellectual figurehead with a book written 20 years ago defining the rationale for global jihad against the West.

But in a book written from inside an Egyptian prison, he has launched a frontal attack on al-Qaeda's ideology and the personal failings of bin Laden and particularly his Egyptian deputy, Ayman al-Zawahiri. ...

Zawahiri has alleged that his former comrade was tortured into recanting. But the al-Qaeda leader still felt the need to compose a detailed, 200-page rebuttal of his antagonist.

The fact that Zawahiri went to this trouble could prove the credibility of Dr Fadl and the fact that his criticisms have stung their target.

Interesting. Doesn't quite fit with the narrative of those who believe everything's America's fault.